One way to harvest solar energy is to use concentrated solar power systems such as concentrated photovoltaic systems that employ optical components to concentrate solar energy (sometimes to great degrees) onto photovoltaic cells. Compact optical systems and components for concentrating solar energy have been developed over the years. Some of these designs comprise a two-stage solar concentrator or collector in which a light focusing layer is optically coupled to a light redirecting layer. The redirecting layer includes a light-guide that guides the sunlight laterally within the light-guide towards a solar collector by total internal reflections with almost no loss of energy. Several examples are shown in United States Patent Application Publication No. 2012/0019942, entitled “Light-Guide Solar Panel and Method of Fabrication Thereof” which is assigned to the applicant of the present application.
One of the difficulties with concentrated photovoltaic systems is that a relatively significant amount of heat (thermal energy) is generated at the photovoltaic cell, which can reduce the efficiency of light-to-electricity conversion by the cell, and should be removed from the cell during operation of the device. In order to transfer this heat away from the cell, conventional concentrated photovoltaic systems typically have the photovoltaic cell on an outer surface of the device, attached a large heat sink. While such designs are adequate for their intended purpose, improvements in this area may nonetheless be desirable.